A method of attaching an upholstery material to a seat pad for automotive seat (hereinafter may be simply referred to as “seat”) includes a hog ring method in which the metal wires embedded in both urethane cushion and upholstery material are fixed by a metal ring; an adhesive method in which cushion and upholstery material are fixed by an adhesive; and a surface fastener mold-in method in which a plastic hook surface fastener embedded in cushion is engaged with a loop surface fastener sewed on the back surface of upholstery material. Recently, the seating portion and backrest of automotive seats are often made into curved shapes in order to easily hold a seating person in position or give a good comfort. Of the above methods, the surface fastener mold-in method is the most preferred in view of easiness of production and easiness of disassembling operation for recycle. However, this method is difficult to be applied to seats with curved surfaces.
An engaging member for use in a mold-in process of a surface fastener which is applicable to curved surfaces of seats is also studied. Patent Document 1 discloses a fastener member in which a plurality of projections with truncated pyramid shape are formed on the base of a tape engaging member, and fastening elements are formed on the surface of the projections, thereby making the tape member deformable in conformity with curved surfaces.
Patent Document 2 discloses a flexible engaging member for mold-in process in which a surface fastener tape is wound and adhered to the surface of a flexible rod having a circular cross-section in a spiral or parallel manner.
Patent Document 3 discloses a hook surface fastener produced by cutting monofilaments which connect two double Raschel-knitted base fabrics at their central portions and melting the tip ends of cut monofilaments which project outwardly from the resulting fabrics. However, the hook surface fastener described in Patent Document 3 is a self-engaging surface fastener having a top hook surface and a back loop surface. Therefore, this patent document describes nothing about integrally uniting a foamed resin layer to the back surface, which is employed in the present invention as described below, and also describes nothing about the mold-in process. In addition, Patent Document 3 is completely silent about the deformation of the resulting surface fastener in conformity with two-dimensionally or three-dimensionally curved surface.
Patent Document 4 describes a self-gripping tape having a hook surface fastener and a foamed layer adhered to the back surface of the hook surface fastener. The base fabric for the hook surface fastener is a knitted fabric and the resulting self-gripping tape is used as a means for attaching a cover material to a foamed cushion for automotive seats. It is described that the self-gripping tape is deformable in its own plane because the base fabric is made of a knitted fabric. However, Patent Document 4 describes nothing about a hook surface fastener which is produced by cutting connecting yarns of a double Raschel-knitted fabric and melting the tip ends of cut yarns into enlarged heads, the use of a surface fastener in mold-in process, and the mold-in process in which a surface fastener is inserted into a recessed portion disposed in a mold and introducing a foamable resin liquid into the mold while keeping the surface fastener in position. This patent document also describes nothing about the effect of the foamed layer united to the back surface for preventing the fastening element surface from being covered with the foamable resin liquid and the effect of the foamed layer for enhancing the ability of deformation in conformity with three-dimensionally curved surfaces. Thus, Patent Document 4 also fails to describe or suggest the subject matter and the effect of the present invention.    Patent Document 1: JP 3794801B    Patent Document 2: JP 3255384B    Patent Document 3: JP 7-184708A    Patent Document 4: JP 11-276214A